A fungus had penicillin before us (humans).  A spider can spin silk that is stronger than steel.  A humpback whale’s fin may be more efficient than the airfoil of an airplane.  Observations like these make me wonder why we spend so much time trying to invent single products.  Each of the above products and many more were invented in nature using a single technique.  Wouldn’t it be easy to copy this technique to make new inventions?

Megan got me thinking about this when she brought the term “evolutionary machine” back from this year’s Evolution meeting.  I’m still not sure exactly what the term means, but my first thought (perhaps incorrectly) was that an evolutionary machine is a self-replicating machine, or alternatively, a computer in which a simulated entity can replicate.  Any amateur naturalist can tell you that organisms are generally well-adapted to their respective environments.  Descent with modification and natural selection is the reason.

I’m not an engineer or a physicist, but I was under the impression that we had equations to describe how fluids move over objects.  So then why are we studying humpback whale fins to improve airfoil design?  Wouldn’t it be easier to put those equations into a computer with the current airfoil design, and let evolutionary forces do the rest of the work?

I see two issues with taking this approach.  The first issue is that our understanding of air flow (or fill-in-the-blank pertaining to the invention of interest) may be imperfect.  This, however, would become obvious during prototype development and product testing, and so subsequent iterations of evolution could be improved by incorporating our newfound knowledge.  The second issue is that we may not know the objective function we are trying to optimize.  For the evolution of organisms, the objective function is a weighted combination of survival and reproduction, termed fitness.  For airfoil design, it is presumably some combination of efficiency, stability, and strength — but obviously some kind of objective function already exists because otherwise we wouldn’t know how great the humpback whale fin is.